changelog: Tighten highlights text.
changelog: Tighten highlights text.

These are limited to 500ch for Google Play; and indeed it feels pretty
long for people to read as it is.  But each of these are such
important changes I hesitate to cut them!

vishwesh3/zulip-mobile,vishwesh3/zulip-mobile,vishwesh3/zulip-mobile,vishwesh3/zulip-mobile